[Thinkpad] High Power USB Port

[Andrew Webber]

It's my understanding that the key is what current (A) the drive
requires.  Some bigger drives require <500mA (I have a 100GB Seagate
that shows 0.45A on its label, it's only 5400 RPM though).  Some
smaller drives require >500mA (I've even seen one, I don't remember
which, where the spec was 1.1A on startup, so presumably even a
double-headed USB cable wouldn't be enough -- you'd need power).

That said, I've heard of USB ports that deliver 1A, perhaps they're
non-standard?  I can't find an example delivering both data and 1A
power right now, but I know my wall charger (converts 110A to USB)
delivers 1A.



-- 
 Andrew                            mailto:awebber at wwwebbers.com

Sunday, February 4, 2007, 9:26:22 AM, you wrote:

> On my X22/23/24, I've had no trouble with external USB drives up to 40b,
> but the 7k 60Gb and 100Gb drives tend to require aux power.  Could be 
> I've just been lucky.  Also, FWIW, I do note anecdotally that with USB
> drives and other accessories like Pocket PCs that the rear USB ports 
> "seem to" dish more power than the side ports.  Never put a meter on 
> them, though.

> - RWM

> Bruce Markowitz wrote:

>> The X20-24 series had low power ports, and would not run any kind of an
>> external drive. The X31 has high power ports, as do all the T4X units I have
>> seen. The RIGHT side port on the X41 is low power, the LEFT port will run
>> external drives. Go figure.
>> ----- Original Message ----- 
>> From: "Donald MacQueen" <dmacq at erols.com>
>> To: "Thinkpad list" <Thinkpad at stderr.org>
>> Sent: Saturday, February 03, 2007 10:49 PM
>> Subject: [Thinkpad] High Power USB Port
>> 
>> 
>> 
>>>I was in Circuit City today looking at a Sandisk USB drive.
>>>
>>>The box said that it required a "High Power USB Port".
>>>
>>>What is that, and how do I know if my TP has one?

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